It absolutely does make sense. Admin exploits or social engineering are not impossible. In any sophisticated software OS that adds any number of features this risk is real let alone a large stagnant one. We see exploits for old code on WinNT kernel all the time. Android and Linux in general are no different - they are far from immune to admin privilege exploit.
You are literally talking about a user gaining administrative privileges, exploiting multiple critical bugs and saying that they should worry about "sideloading". I think you have serious "security" issues.
In the end all you are doing is spreading missinformation just because you like apple more.
The only real security concern is from the apps you decide to sideload. Without express permission those apps can't be installed and to access your data you have to give them again permissions.
Fact: the only reason Apple doesn't permit it is because they can't control the payment options of such an app. You would also be able to install a browser like Chrome or Firefox that doesn't use their crappy and outdated engine from safari.